Mark the letter A, B, C, or D on your answer sh...

Câu hỏi: Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Visitors to the park must pay an entrance and boat fee, which is approximately $60 regardless of the number of people__________.

A. on aboard

B. on the board

C. aboard

D. boarding